血流与脉搏波的多模型耦合建模与计算

Cardiovascular disease is the leading cause of death within China and worldwide. In the pathogenesis of atherosclerosis, thrombosis, hypertension and other major cardiovascular diseases, the complex interactions between blood flow and vessel structures play a crucial role. To better understand the pathogenesis of these diseases and investigating disease prevention, diagnosis, and treatment strategies, it is necessary to study the behavior of blood flow under different states of patients and to explore the interaction between the behavior of blood flow and the structure of the entire circulatory system. In this project, our group will establish a coupled model for blood flow and a fast computation platform for the coupled model. This coupled model includes a one-dimensional model for propagation of blood pulse waves in large arteries, a three-dimensional model for interaction between local blood flow and elastic vessel walls, a model for blood flow regulation in organs and tissues under different states, and an adaptation model for diameters and wall thicknesses of blood vessels. Based on the coupled model and the computation platform, the team will focus on a few scientific problems, including the behavior of the blood flow in a few important blood vessels, the behavior of blood flow in vein grafts, and the effects on blood flow of the change of patient states and the change of vessel structures such as arteriosclerosis. This project will provide a systemic platform for the computation of blood flow, thus vigorously promote a wide application of scientific computing in the study of cardiovascular diseases.

心脑血管疾病是中国和全球范围内的首要致死病因。在动脉粥样硬化、血栓、高血压等重要心血管疾病的发病过程中，血流行为与血管的复杂相互作用影响至关重要。为了深入理解这些疾病的发病机制，针对性的探讨疾病诊断、预防和医疗策略，人们有必要对人体不同状态下不同局部的血流行为进行深入研究，并探讨血流行为与血管结构及整个循环系统的相互影响。在本项目将建立不同层次和角度的血流模型的耦合模型，包括全身大动脉内脉搏波一维模型、局部血流与血管壁相互作用的三维模型、不同状态下组织血流调节模型以及血管管径和厚度的适应性生长模型，同时通过发展和设计快速算法搭建全身关联的血流计算平台。在此基础上，团队将针对关键部位的血流行为、静脉移植后局部血流行为、人体状态变化和血管结构变化对局部血流的影响等科学问题进行深入研究。这一研究成果将提供一个全身关联的血流快速计算平台，大力促进高性能科学计算在心血管疾病研究中的广泛应用。

随着生产力水平和国民经济的不断发展，国民预期寿命不断延长，心血管疾病逐渐成为威胁国民健康的最主要因素。已有的研究表明血管及其网络结构与血流的相互影响是绝大部分心血管疾病的发病原因，加深对这种相互影响的理解对心血管疾病的诊断、治疗和预防具有重要意义。.本项目在已有模型的基础上，结合大量已有的实验数据，建立和发展了多种尺度上的血流与血管结构相互作用模型，包括一维脉搏波模型、三维血流模型、血管适应性生长模型、血管生成模型和血流自调节模型等，并通过这些模型的相互耦合，理解不同层次和尺度上的模型之间的相互影响。项目针对相关模型数值模拟的难点开发了多个快速算法，包括全身大动脉内脉搏波传播的快速算法、具有复杂血管网络（微血管数目达到数千至数万）的组织内氧气供给和消耗的快速算法等。在此基础上，项目实现了组织内复杂血管网络的适应性生长和血管生成的模拟。通过这些模拟，项目利用模型成功预测和解释了实验中观察到的斑马鱼脑血管剪枝现象，并对氧箱内早产小鼠微血管稀疏化等实验现象给出了初步解释。.项目提出的模型和算法的进一步完善和广泛应用将有助于对高血压等心血管疾病的发病机制提出新的理解，并为这些疾病的针对性提出有益的研究方向。